The intrathoracic compliance chamber (ICC) is the most successful solution to the variable volume problem of a totally implanted pulsatile artificial heart. However, existing designs are compromised by the rate at which gas permeates through he chamber walls, given that all polymeric membranes are subject to some degree of gas permeation. Given this limitation, percutaneous gas refills would be required at frequent intervals, measured in weeks. It is the applicants' hypothesis that this limitation can be remedied by the use of liquid crystal polymers (LCPs), a material class of remarkable mechanical properties, high chemical inertness, and extremely low permeability (essentially equivalent to glass). The applicants proposes to develop the materials and processes for the fabrication of vastly improved ICCs. The applicants plan to demonstrate that LCPs have the biocompatibility, low permeability, high fatigue resistance, and sufficient manufacturability to be ideal candidates for ventricular assist system and artificial heart compliance chambers. PROPOSED COMMERCIAL APPLICATION: NOT AVAILABLE